Acoustic Overstability of Plane Parallel Polytropes: an Astrophysical Thermoacoustic Engine

Details Acoustic Overstability of Plane Parallel Polytropes: an Astrophysical Thermoacoustic Engine Acoustic Overstability of Plane Parallel Polytropes: an Astrophysical Thermoacoustic Engine

Dec 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997aas...191.1208u&link_type=abstract

American Astronomical Society, 191st AAS Meeting, #12.08; Bulletin of the American Astronomical Society, Vol. 29, p.1228

Astronomy and Astrophysics

Astronomy

Scientific paper

We examine the stability of nonadiabatic acoustic modes in a plane parallel atmosphere in a constant gravitational field where the source of nonadiabaticity is thermal conduction with constant coefficient. This prescription filters out the effects of the kappa -mechanism. The static state is described by polytrope solutions where the density is related to the linear temperature profile via a power law relation described by the usual polytropic index m. We solve the resulting fourth order boundary-value/eigenvalue problem describing perturbations by utilizing a variety of asymptotic and numerical methods. Disturbances are shown to be unstable under a variety of parameter regimes including conditions where the background polytrope is either super- or subadiabatic. Two main instabilities emerge and in one of them its resemblance to the thermoacoustic engine is drawn. We also find that it is most clearly heard when the conduction parameter is strong. For this extreme circumstance marginal stability conditions are derived and are used to motivate and derive weakly nonlinear amplitude equations for this problem.

Affiliated with

Also associated with

No associations

Rating

Acoustic Overstability of Plane Parallel Polytropes: an Astrophysical Thermoacoustic Engine does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Acoustic Overstability of Plane Parallel Polytropes: an Astrophysical Thermoacoustic Engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Acoustic Overstability of Plane Parallel Polytropes: an Astrophysical Thermoacoustic Engine will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1173032